A retired navy captain imprisoned 10 months ago after reporting on radioactive waste contamination by Russian nuclear submarines was freed Saturday, in a setback for the state security police. Capt. Alexander Nikitin still faces charges of treasonous disclosure of military secrets. But his release, ordered by Russia's deputy prosecutor-general, appeared to be "the first step, a very important step" toward exoneration, Nikitin's lawyer said.

Nevada Gov. Kenny Guinn on Monday vetoed the use of Yucca Mountain as the nation's underground repository of highly radioactive nuclear waste, declaring that the $60-billion proposal is "based on bad science, bad law and bad public policy." In February, President Bush recommended to Congress that Yucca Mountain, 90 miles northwest of Las Vegas, serve as a permanent burial ground for the nation's 77,000 tons of spent nuclear fuel. "Let me make one thing clear, crystal clear in fact.

The most compelling argument for building a low-level nuclear waste disposal facility in the California desert at Ward Valley has always been that such waste is accumulating faster than it can be safely disposed of. Now comes a Nebraska economics professor with persuasive evidence that this dump is not needed at all. He also argues that disposal at Ward Valley would be more expensive for hospitals and other waste generators than if they continued to use existing dumps.

A bill that would enter California into a low-level nuclear waste disposal agreement with South Dakota was narrowly approved by an Assembly committee Tuesday over opposition of the Deukmejian Administration. The measure, by Assemblyman Steve Peace (D-Chula Vista), complies with a federal law that requires states to create their own dumps or form compacts with other states to jointly dispose of such wastes.

The Environmental Protection Agency on Wednesday set a stringent ground-water protection standard for the proposed repository for spent nuclear fuel at Nevada's Yucca Mountain. The announcement of public health and safety standards for the site was a key step in the process that must be completed before President Bush announces his decision on whether to start a licensing process for Yucca Mountain.

Yielding to protests from Japan and the United States, Russia agreed Thursday to stop dumping liquid radioactive waste into the Sea of Japan but warned that it will resume the practice unless richer countries help it process the waste for underground burial. Environment Minister Viktor Danilov-Danilyan announced the decision after a Cabinet meeting. He said Russia will refrain from further dumping "in the near future."

A decision to bury thousands of tons of nuclear waste in Nevada should be overturned because the government cannot assure the site's geology will keep radiation from seeping into the environment, the state of Nevada has argued in a court filing. The brief, filed in a suit challenging the decision to entomb the waste at Yucca Mountain, maintained that the Energy Department violated the 1982 Nuclear Waste Policy Act by resorting to "engineered barriers" to contain the waste.

At the local Elk's Lodge in this dusty, overgrown truck stop, 16 of the nation's leading geologists, geophysicists and geochemists Thursday began assessing the wisdom of burying radioactive waste in a desolate strip of the eastern Mojave Desert 20 miles to the west.

Just before dawn one day last month, in a million-gallon caldron encased in reinforced concrete and buried six feet underground, a vile brew of radioactive waste heaved and gurgled, and then--right on schedule--emitted a huge burp of hydrogen. For reasons that scientists do not understand, this unnerving drama has been recurring every 80 to 109 days for the past 10 years. From seething sludge at the bottom of Waste Tank 101-SY at the sprawling Hanford U.S.